A person who has normal sexual intercourse without contraception for 1 year after marriage and fails to conceive is called infertility. The male factor accounts for 30% to 40% of these cases, while 6.1% ~3.6% are obstructive azoospermia (OA). The obstruction that causes azoospermia can occur in any part of the male spermatic tract, such as the testicular network, epididymis, vas deferens and ejaculatory ducts. The main causes of obstruction are vasectomy, genitourinary tract infections, congenital diseases and medically induced injuries. The majority of OA occurs in the vas deferens and epididymis. Microsurgical vasectomy (VV) and epididymal vasectomy (VE) have greatly improved the overall success rate of OA surgery, allowing most OA to be surgically reopened to the sperm duct and conceive naturally, while some OA still requires surgical sperm retrieval and assisted reproductive techniques to conceive. Evolving microsurgical techniques have led to a gradual increase in the surgical cure rate for obstructive azoospermia, and studies have confirmed that microsurgery is an effective treatment for obstructive azoospermia and is more cost-effective than assisted reproductive techniques. Among them, the etiology of obstructive azoospermia is infection in 8 to 46% of patients, who have a clear history of previous genitourinary infections, especially bilateral epididymitis, and a variety of pathogens such as; gonococcus, chlamydia, trichomonas, brucellosis, BCG, mycoplasma, E. coli group of bacteria, adenovirus and enterovirus are reported to cause epididymitis. Regardless of the cause of epididymitis, after the acute inflammation period, a fibrous scar will be formed locally in the epididymis, causing obstruction. On physical examination, there are obvious hard nodules in the epididymis, and most of the obstruction points in the epididymis are at the hard nodules. In epididymitis with tuberculosis infection, the semen volume is reduced, and bead-like changes in the ejaculatory duct can be palpated on physical examination. Epididymitis can be treated promptly in areas with good medical care, and the proportion of renewed OA is low, whereas in developing countries and regions, infection-induced obstruction accounts for a higher proportion of all OA. Sexually transmitted diseases (STDs) were reported to be the cause of 29.4% of male infertility patients diagnosed in a tertiary care hospital in Nigeria. In a study of infertility in western Siberia, 8.6% of male infertility was found to be due to post-infectious OA, and an additional 4.3% of men had an accessory gonadal infection. A study of infertile couples in Mongolia found 8.4% of post-infectious OA and 6.7% of accessory gonadal infections in infertile men. Most post-infectious OA can be treated by scrotal exploration and microsurgical reconstruction of the seminal tract, except for post-tuberculous OA. Tuberculosis infection causes multiple obstruction of the seminal tract and surgical results are poor. It is recommended that after the diagnosis of tuberculosis, active anti-TB treatment should be given first, and artificial assisted reproduction techniques can be used if natural conception cannot occur after tuberculosis is cured. Many patients forget or do not realize that they have had reproductive infections such as epididymitis, and such cases are considered as unexplained obstructive azoospermia, and the proportion of OA after infection in male infertility may be underestimated.